Like all Brits, I love an underdog – so a part of me always loved Colin Baker's Doctor. I used to put his bad ratings, bad reviews and eventual sacking down to the mendacity of the BBC and a couple of production glitches that could've been ironed out with more time. But then, in the course of researching this blog, I re-watched the serial Timelash and realised I was wrong. The sets are bad, the acting is bad, the script stinks, the effects are laughable and – most importantly – Colin's Doctor is simply unlovable. Timelash, by the way, is an anagram of Lamesh*t.

Why did Colin get the part? Well, John Nathan Turner – the eccentric producer of the show – met him at a wedding and thought he was quite amusing. So he offered him the role. Error #1: don't hand out to jobs to random people you once shared a finger buffet with. Error #2: don't give your new actor a costume that makes the viewer want to throw up. Seriously, the Sixth Doctor's costume was not only an ugly design but a major production flaw. It meant that everything had to be exaggerated to compete for the viewer's attention. Peri's costume had to be smaller and tighter, the sets floodlit and Baker's acting much hammier – not that he needed much encouragement.

I'm being unfair. Colin Baker can act and was sometimes quite affecting in the role. But he was the victim of a series of bad production decisions and bad scripts. It was decided to make his character initially unlikeable, to have him grow into a more sympathetic person as time wore on. The problem was that the development never really happened and he just stayed unlikeable. He bickered with his companion, Peri, and dispatched his enemies cruelly – using cyanide and even an acid bath. Sometimes, all the darkness and depravity worked. Revelation of the Daleks, written by the series script editor Eric Saward, is a triumph of comic nihilism (see clip above). Davros, it reveals, has set up shop as a funeral director – and has been turning all the corpses into food to feed the galaxy. The tone is blackly ironic and an indicator of the more adult direction that Saward would've taken the show if he'd got his own way. One of the characters in Revelation is a cosmetic surgeon with wandering hands and kinky sexual tastes. When he propositions Peri, she says, "Over my dead body!" The surgeon eagerly replies, "Can't wait!"

But Saward had to share production responsibilities with John Nathan Turner – and JNT was a panto man. After producing a first season that was an unlikely mix of grim and camp, Who was taken off the air for 18 months by the BBC bigwigs and told to get its house in order. Bizarrely, JNT thought the way to turn things around was to hire Bonnie Langford as a companion, a squeaky actress best known for floating around theatres on a wire as Peter Pan. Bonnie was to acting what Russell Brand is to politics – and she contributed to the sense of creeping crud that engulfed the show. By the end, it was pure amateur hour. As Colin Baker said of the serial Mindwarp:

I was very confused by it … because there was a point when I said to Eric Saward, the script editor, ‘When I’m tying Peri to this rock and threatening to torture her, am I doing it for some subtle reason of my own, because I think I’m being watched or whatever, or because I’ve been affected by [a] mind probe, or is the Matrix [which is relaying the story to a jury judging the Doctor's actions] lying?’. Those were the three alternatives as I saw it. He said ‘I don’t know, you’d better ask [the writer] Philip Martin’, so I got in touch and gave him those three alternatives, he said ‘I don’t know, Eric wrote the trial stuff, all the Matrix stuff was added after, by Eric, you’d better ask him’. So I went to John Nathan-Turner, he said ‘Oh, whichever you like’. This is the level of involvement … Eric was going through his own problems at the time, disagreeing with John Nathan-Turner on all sorts of things. I felt that was all very sloppy, it was all cobbled together a bit … You expect the writers to know what’s happening, but that’s not always the case.

But was it all truly terrible? No. As Revelation of the Daleks showed, there was potential in Baker's more angry, less morally certain Doctor and his epoch contained plenty of fine moments. Peri being given the brain of a slug and losing all her hair; Jacqueline Pearce falling to her knees and licking blood off the floor; hands appearing from the sand on a beach and dragging the Doctor down to Hell… And Colin was probably the most poetic of the Doctors. As he observed in words that could easily have been an epitaph for the series, "Planets come and go. Stars perish. Matter disperses, coalesces, forms into other patterns, other worlds. Nothing can be eternal."

Not even a show as wonderfully frustrating as Doctor Who.

ADDENDUM: Mr Baker tweeted after this post went up to point out that JNT knew of his work before he attended the wedding – and I'm sure he did. After all, CB was an established TV actor with parts in War and Peace and The Brothers. But, for all his undeniable talents, I stand by my assertion that it just didn't work on Who…